1. Field of the Invention
The present invention relates to a mail sequencing system. More specifically, the present invention relates to a system that automatically sorts or sequences non-standard-size type mails for each destination.
2. Description of the Related Prior Art
A prior art non-standard-size mail sequencing system discriminates between the destinations of mails from their identified address and zip code and stacks the mails onto stacking trays provided in a plurality of sorting bins. The destinations are limited by the number of the sorting bins. A full tray is discharged automatically to the outside of the sorting bins to be carried by a conveyer. In the sorting bins from which the full tray is discharged, a lamp is lit up, and then, the operator supplies an empty tray. An example of such system is disclosed in Japanese Patent Application Laid-Open No. 59-090679. The system disclosed by the publication has a plurality of induction lines. In each of the induction lines, mails are separated one by one. A scanner captures the image of the mail. A synchronization carrying mechanism operated in synchronization with movement of a carrying box puts the mail into the carrying box. The carrying box including the mail is moved to a desired sorting bins identified by an image process. A controller is driven for unhooking the carrying box to open its bottom plate. The mail is dropped into a stacking box. The sequencing system processes non-standard-size mails having a length of about 40 cm and typically has at most about 300 to 400 sorting bins. In this case, even when the sorting bins are set in two upper and lower layers, the system length reaches 40 to 50 m. It is thus difficult to increase the number of the sorting bins stacking the mails so as to further sort the destinations of the mails in delivery order.
In a standard-size mail sequencing system, typically, the operator manually re-supplies once-sorted mails to a feeder mechanism for sorting twice. The mails can be further sorted. A system having 33 sorting bins performs sorting twice so as to sort delivery points of 33×33=1089. In this case, standard-size mails are sorted. The operator can manually process the mails stacked in the sorting bin. The operator can carry the mails relatively easily from the sorting bin to the feeder. The prior art non-standard-size mail sequencing system cannot easily perform sorting twice as described above. Non-standard-size mails are processed. The weight of the mails stacked onto one tray is significantly large. It is difficult for the operator to manually perform the operation. The sequencing system has to be larger.